Outline

Objective: We investigated if intrasurgical electrical stimulation of proximal nerve stumps (ES) speeds up peripheral nerve regeneration (PNR) across long gaps. Furthermore, we were interested if functional motor recovery (FMR) would be facilitated by the treatment.

Methods: Sciatic nerves of adult rats were transsected proximally to their trifurcation. Animals were divided into a non-stimulated control group (A) and an electrically stimulated group (B). ES (1h, 20Hz) was applied using a special electrode. Silicone tubes were used to bridge a 13mm gap between the separated nerve stumps. Transplantation of Schwann cells (SC) is known to facilitate PNR across long gaps. Therefore, silicone tubes were differentially filled for acellular (A-1, B-1) and cellular (A-2, B-2) transplantation conditions. In A-1/B-1, tubes were filled with growth factor-reduced Matrigel (GFR-Matrigel). In A-2/B-2, highly enriched neonatal rat SC were suspended in GFR-Matrigel.

Conclusions: ES demonstrates potential to increase PNR across long gaps. This capacity is dependent on the presence of transplanted SC. Morphometrical analyses of regenerated myelinated axons as well as quantification of retrogradely labelled regenerating neurons are currently performed to further estimate the quality of PNR. Follow-up studies will be initiated to elucidate the potential to improve FMR by intrasurgical short-term electrical stimulation. Financial support: Stiftung Neurochirurgische Forschung, HiLF-program Hanover Medical School. * R. Schmitte, D. Klode contributed equally.